Hi Everyone: I am looking into going to Norway this Summer with some friends. We will be going to Norway, Finland & Sweden to do some kayaking & touring and then to Estonia, Latvia, & Lithuania to do some bike riding & touring. We have our choice of August or September travel.
The causes are varied and many. One thing is for certain. A horse that stumbles is a danger to the rider as well as to himself. Potential Reasons for Stumbling and Tripping (forelimbs) in Horses. 1  Long toes. 2  Tripping in the Forelimbs. 3  Hoof imbalances. 4  Laziness. Not balanced.  Green 1  Horse. Not fit/Poor muscle  tone.
I don't know why, but lately the solution is purge valves. I suppose that would depend on what EVAP code you got, though...you could have a broken hose at the charcoal canister which would be unrelated to the stumbling. That said, a purge valve will cause exactly those symptoms (a random misfire), and hard starting.